JASON Hall had driven out of the Mount Thorley Warkworth mine early on Sunday afternoon with his older brother, Jeffrey, heading west to attend a funeral.

But the pair made it only five kilometres along the Golden Highway before their Toyota Kluger was involved in a head-on collision at Jerrys Plains with a Ford utility, being driven by Central Coast man Bruce Byers.

All three men were killed, while a 52-year-old woman who was a passenger in the utility was flown by Hunter Westpac rescue helicopter to John Hunter Hospital.

She was listed as being in a serious but stable condition last night.

The families of all three men were attempting to come to terms with the massive tragedy on Monday, as details emerged on how fate got them to meet on the dangerous piece of road made even more treacherous with the first real rain in the region for months.

The were all too distraught to speak publicly.

Jason, 40, of Bolwarra Heights, and Jeffrey, 44, of nearby Aberglasslyn, were contractors at the Rio Tinto-owned open-cut mine.

They left early during the day shift to make the trip for a funeral that was held yesterday.

Normally, they would be working a 12-hour shift before turning in the opposite direction out of the mine to head home.

Mr Byers, of Charmhaven, and his passenger were travelling east along the highway when the accident occurred.

Crash investigators are looking into what may have caused the Kluger to move from its lane.

‘‘This is a tragic event for the families of the people involved and for people in our team at Mount Thorley Warkworth,’’ the mine’s general manager of operations Cam Halfpenny said.

‘‘We offer our sincere condolences to the families who have been affected.

‘‘We have made contact with the family to offer them our support and we are also providing access to counselling for our employees.’’

The three deaths brought the Hunter’s road toll during a horrific four days to six, following the deaths of two women and another young man.

Chief Inspector Le-Merton said police were investigating whether speed was a factor in the death of Cessnock man Jake Hain as he drove home from work at Pokolbin on Wednesday, his girlfriend watching on as she followed in another vehicle.

He said it appeared a Mudgee woman had disobeyed a stop sign before driving into the path of a truck at the intersection of the New England Highway and Golden Highway at Whittingham on Thursday.

‘‘If we really want to talk about what has happened this week, then we need to be talking about driving to the conditions,’’ Chief Inspector Le-Merton said.

‘‘Do not just drive to the speed limit, drive to what is safe at that moment.’’